Today we are going to review the major of sound cards from TerraTec - Aureon 7.1 Space on multi-channel VIA Envy24HT audio-controller, which was announced in the end of 2002 and belongs to the new generation of eight-channel sound cards.

As we have already said above, Aureon 7.1 Space is based on the improved version of the audio controller (Envy24HT), so we decided to compare Aureon with DMX 6fire audio card based on ICE1712 Envy24. Unlike Creative cards, which have been developed for the multimedia market from the very beginning, the above-mentioned cards from TerraTec went down to us from the professional audio cards niche. We include Audigy2 test results here, too, so you will be able to compare Aureon with Audigy2 (click here for our detailed review of Audigy2). For our tests we used SpectraLAB software suite (v.4.32.17), which consists of two parts: a signal generator and analytical-measuring part. Before the tests, we turned off all the audio surround effects that might bring distortion into the output signal.

To find the value of signal/noise ratio (SNR), total harmonic distortion (THD) and intermodulation distortions (IMD), the software signal generator emitted tone signals of a certain shape. They were 1kHz signal for SNR and THD and the standard set of two low and high frequency tones (LF = 250Hz, HF = 8020Hz) for IMD.

The SNR is the ratio of the useful signal level (here, it's 1kHz signal) to the noise level in all frequencies of the spectrum. The higher is the SNR, the better. The calculations are performed by the analytical part of the test program, displaying the results in real time.

The THD is the ratio of the harmonic capacity to the fundamental capacity. THD is calculated by seeking the peak frequency in the spectrum (and the base). The overall capacity in separate frequency harmonics is determined relative to it. The overall noise level is not counted in calculations (it’s used in the THD+N parameter). Lower value of this parameter (in percents) indicates better sound purity. THD is always calculated with the 1kHz reference signal.

The intermodulation distortions (IMD) parameter shows the percent of distortions when two tones are mixed together. The typical IMD calculation is done with 250Hz and 8020Hz tone signals with the high frequency tone fading to the low frequency one by 12dB (4:1 ratio). In order to prevent random noises from interfering with the results, the IMD is calculated after a series of tests.

TerraTec Aureon 7.1 Space spectrograms

44,100Hz / 16bit

Determining IMD at 44,100Hz / 16bit

48,000Hz / 16bit

Determining IMD at 48,000Hz / 16bit

TerraTec DMX 6fire spectrograms

44,100Hz / 16bit

Determining IMD at 44,100Hz / 16bit

48,000Hz / 16bit

Determining IMD at 48,000Hz / 16bit

The results are listed in the table:

CreativeAudigy2

TerraTec Aureon 7.1 Space

TerraTec DMX 6fire

44,100Hz / 16bit

48,000Hz / 16bit

44,100Hz / 16bit

48,000Hz / 16bit

44,100Hz / 16bit

48,000Hz / 16bit

SNR, dB

90.114

90.322

93.13

93.071

95.967

96.069

THD, %

0.00203

0.00422

0.00157

0.00194

0.0009

0.00095

THD+N, %

0.00312

0.00384

0.00221

0.00222

0.00159

0.00157

IMD, %

0.0202

0.0078

0.0044

0.0039

0.0016

0.0015

The results prove that Aureon 7.1 Space is a very high class product, which surpassed Audigy2 in all tests and was just a little worse than the more expensive DMX 6fire. Aureon produces very pure sound, with the noise level below -100dB mark. The low percent value of THD suggests that there are no significant harmonics peaks. All this is clearly seen in the spectrograms. Of course, such minute advantages are not perceptible by ear and we won’t contend that Aureon is indisputably better than Audigy2. There are also such factors as functional software where Audigy2 beats its opponent. Moreover, both sound cards are targeted at the mass user who doesn’t demand as much from the product as a man who is professionally into music.

When perceived by the ear, Aureon 7.1 Space did very well reproducing life-like timbres and pure sound. High-quality speaker systems provided a necessary stereo-panorama width in an ordinary-sized room. Together with the fundamental basses this allowed us to enjoy excellent and precise sound sources positioning and their stable perception at any volume level. Actually, you can adjust anything with the mixer, but we didn’t feel any discomfort at all, so it was mostly playing with the feature just for fun.

One problem we had with Aureon 7.1 Space was that the card refused to give out any sound in some gaming applications, especially after Sensaura was enabled. The problem was solved by installing up-dated drivers from the technical support page (it was 5.1.2600.11 driver dated 10.02.03). That’s about all.